S50 Hardware User Guide
1VV0301505 Rev. 3
Page 16 of 60
2021-05-05
Not Subject to NDA
Pin Name
State: S50
TESTMODE#
Input floating (disconnected)
BOOT0
Input floating (disconnected)
SWDIO
Input with pull-up
(1)
SWCLK
Input with pull-down
(1)
(1)
pull-up, pull-down: R
PU,
R
PD
is typ. 10k
Ω
Table 2: Pin States during Reset
4.3.
Serial Interface
The serial interface of S50 is a high-speed UART interface supporting RTS/CTS
flow control and interface-up/down mechanism according to the UICP protocol (refer to
[2]).
•
Electrical interfacing is at CMOS levels (defined by VSUP; see chapter 0)
•
Transmission speeds are 9600
–
921600 bps and 1Mbps (asynchronous)
•
Character representation: 8 Bit, no parity, 1 stop bit (8N1)
•
Hardware flow-control with RTS and CTS (active low)
Note/Tip: Transmission speed may be limited by firmware. See
corresponding AT command reference [3] for further information.
4.3.1.
Basic Serial Interface
The basic serial interface (with RTS/CTS flow control) uses only four signal lines (UART-
RXD, UART-TXD, UART-CTS#, UART-RTS#) and GND. IUR-IN# and IUR-OUT# (see below)
can be left unconnected.
S50
Host
UART-RXD
UART-TXD
UART-CTS#
UART-RTS#
GND
Figure 5: Basic Serial Interface
